### Data Structure & Algorithm Interview Questions And Answers - Part VI.

Here, are some sample questions based on "Data Structures". Read it carefully as these questions will help you in cracking any interview.

26) What are the different types of arrays?

Arrays are of different types namely one-dimensional arrays, two-dimensional arrays and multi-dimensional arrays. One-dimensional arrays comprise of finite homogeneous elements while multi-dimensional arrays comprise of elements, each of which is itself an array.

27) What do you mean by the base address of an array?

In memory, one-dimensional arrays are implemented by allocating a sequence of addressed locations so as to accommodate all its elements. The starting address of the very first element of the array is called base address of the array.

28) Give the formula to calculate the address of any element in an array, when the length of the array along with its base address and size of the element are given ?

The formula to calculate address of any element in an array is:

Address of the element with subscript I = Base address + ES (I – L)

- Where ES is the size of an array element;
L is the lower bound of the array and all array elements are of the same size.

29) How is computer memory allotted for a two-dimensional array ?

For two-dimensional array, the computer memory is allotted either in Row-major form or in Column-major form.

Row-major form stores the 2-D arrays row wise i.e. firstly the first row is stored, then the second row, then third row, and so forth.

Column-major form stores the 2-D array column wise i.e. firstly the first column, then the second column, then third, and so forth. The default form is Row-major.

30) What is the difference between an array and a stack housed in an array?

An array is a group of homogeneous elements stored in contiguous memory locations. The elements in an array can be processed from anywhere in the array.

A stack implemented as an array has elements stored in contiguous memory locations. But a stack is always processed in a LIFO manner i.e. Last in First out manner wherein the elements can be added or removed from the top end of the stack. That is why a stack is also called a LIFO data structure.

31) List the basic operations which can be performed on data structures ?
32) How can you calculate the size of an array, given the upper and lower bounds of the array ?
33) Which are the two very common search techniques and what are their mechanisms ?
34) Describe how linear search is carried out ?
35) How does the binary search work ?

36) What are the differences between linear search and binary search ?
37) State the condition(s) under which binary search is applicable ?
39) What is sorting of an array ? Name a few types of sorting techniques ?
40) What is the mechanism of selection sort ?